Stady of the structure, hardness and magnetic characteristics of austenitic steel 04Kh17N8T with varying surface hardening modes

Surface plastic deformation is widely used in various branches of mechanical engineering to improve the operational properties of materials. The paper presents the results of the study of the influence of surface plastic deformation modes on the structure, microhardness and magnetic characteristics of austenitic steel 04Kh17N8T. The experiments included changing the parameter of surface plastic deformation — normal load on the indenter. Using microstructural analysis, including optical and electron microscopy, changes in the crystalline structure of the material after deformation were analyzed. The magnetic characteristics of the samples were determined using a Barkhausen noise analyzer. It was found that the hardness of the samples in the cross section is almost the same at indenter load of 250 N and more. In addition, there is a correlation between deformation modes and hardness. It is shown that changing the modes of surface plastic deformation has a significant effect on the structure and magnetic characteristics of 04Kh17N8T steel. Friction treatment leads to the formation of a gradient structure with a depth of up to 500 μm, and at a depth of up to 25 μm a highly deformed dispersed structure is formed. Due to the increase in the normal load on the indenter during friction machining, the content of defects in the material increases, which affects its magnetic properties. The obtained results can be used in the improvement of surface plastic deformation technologies and optimization of steel processing processes to achieve the required level of performance characteristics and increase the service life of parts and structural elements.